Hvac unit actuator enclosure

ABSTRACT

An enclosure for an actuator of an HVAC unit includes a hollow member with an inner shell, an outer shell, and an insulation layer disposed between the inner shell and the outer shell. A cavity within the inner shell operates to receive an actuator. An exterior surface of the hollow member has curvilinear shape configured to limit resistance to airflow over the exterior surface. A base of the enclosure is connected to a first end of the hollow member and a cover is detachably coupled to a second end of the hollow member opposite the first end.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority from and the benefit of U.S. Provisional Application Ser. No. 63/300,990, entitled “ENCLOSURE FOR AN ACTUATOR OF HVAC UNIT,” filed Jan. 19, 2022, which is hereby incorporated by reference in its entirety for all purposes.

BACKGROUND

This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present techniques, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.

A heating, ventilation, and/or air conditioning (HVAC) system is often utilized to regulate environmental conditions, such as temperature and/or humidity, within a building or other conditioned space. For example, an HVAC system may include equipment, such as one or more heat exchangers deployed in an HVAC unit, which operates to produce temperature-controlled air. To facilitate supply of the temperature-controlled air to a conditioned space, actuators may be employed to operate HVAC components such as air dampers, fluid valves, air handling units, and other components. For example, an actuator can be coupled to a damper in an HVAC system and can be used to drive the damper between an open position and a closed position. An actuator typically includes a motor and a mechanical operator or drive device (e.g., a hub, a drive train, driveshaft) that is driven by the motor and coupled to an HVAC component (e.g., a damper).

SUMMARY

This section provides a brief summary of certain embodiments described in the present disclosure to facilitate a better understanding of the present disclosure. Accordingly, it should be understood that this section should be read in this light and not to limit the scope of the present disclosure. Indeed, the present disclosure may encompass a variety of aspects not summarized in this section.

An enclosure for an actuator of an HVAC unit in accordance with present embodiments includes a hollow member with an inner shell, an outer shell, and an insulation layer disposed between the inner shell and the outer shell. A cavity within the inner shell operates to receive an actuator. An exterior surface of the hollow member has a curvilinear shape configured to limit resistance to airflow over the exterior surface. A base of the enclosure is connected to a first end of the hollow member and a cover is detachably coupled to a second end of the hollow member opposite the first end.

A ventilation system in accordance with present embodiments includes a damper configured to be driven by an actuator to open and close to control airflow through a flow path of the ventilation system. An enclosure is mounted on the damper and a hollow member of the enclosure defines a cavity configured to receive the actuator therein. An exterior surface of the hollow member has a curvilinear shape configured to limit resistance to the airflow passing over the enclosure. A base is connected to a first end of the hollow member, and a cover is detachably coupled to a second end of the hollow member opposite the first end.

A tunnel ventilation system in accordance with present embodiments includes an airflow path for ventilation of an interior space, a damper configured to transition between an open configuration and a closed configuration to control airflow through the airflow path, and an actuator configured to transition the damper between the open configuration and the closed configuration via a mechanical operator directly or indirectly coupled to the damper. An enclosure is mounted on the damper and positioned within the airflow path. A hollow member of the enclosure is formed from an inner shell, an outer shell, and an insulation layer disposed between the inner shell and the outer shell, wherein the hollow member defines a cavity in which the actuator is disposed. An exterior surface of the hollow member has a curvilinear shape that is configured to limit resistance to the airflow passing over the enclosure. A base is connected to a first end of the hollow member, and a cover is detachably coupled to a second end of the hollow member opposite the first end, wherein the cover comprises a port through which the mechanical operator extends.

Those skilled in the art will appreciate that the summary is illustrative only and is not intended to be in any way limiting. Other aspects, inventive features, and advantages of the devices and/or processes described herein, as defined solely by the claims, will become apparent in the detailed description set forth herein and taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Various aspects of the present disclosure may be better understood upon reading the detailed description and upon reference to the drawings, in which:

FIG. 1 is a perspective view of an embodiment of a heating, ventilation, and/or air conditioning (HVAC) system for environmental management in accordance with present embodiments;

FIG. 2 is a perspective view of a ventilation system (e.g., a tunnel ventilation system) in accordance with present embodiments;

FIG. 3 is a schematic cross-sectional representation of an actuator housed within an enclosure of the ventilation system of FIG. 2 , in accordance with present embodiments;

FIG. 4 is an exploded perspective view of an enclosure housing an actuator in accordance with present embodiments;

FIG. 5 is an exploded perspective view of an enclosure including a latch extending from a hollow member to couple with a cover such that the enclosure houses an actuator in accordance with present embodiments;

FIG. 6 is an exploded perspective view of an enclosure and layers of the enclosure in accordance with present embodiments; and

FIG. 7 is a cross-sectional temperature gradient diagram of an enclosure indicating results of a thermal analysis of the enclosure in accordance with present embodiments.

DETAILED DESCRIPTION

One or more specific embodiments of the present disclosure will be described below. These described embodiments are only examples of the presently disclosed techniques. Additionally, in an effort to provide a concise description of these embodiments, all features of an actual implementation may not be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but may nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.

When introducing elements of various embodiments of the present disclosure, the articles “a,” “an,” and “the” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. Additionally, it should be understood that references to “one embodiment” or “an embodiment” of the present disclosure are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features.

As will be discussed in further detail below, a heating, ventilation, and/or air conditioning (HVAC) system, such as one including an air conditioner, a heat pump, and/or a tunnel ventilation system, may include one or more ventilation systems for airflow routing and flow control that may require operation under extreme conditions. A tunnel ventilation system, for example, may include one or more air movers (e.g., fans) installed at a first port of a passageway and an air inlet at a second port of the passageway such that a tunnel effect is created as air flows through the passageway. Flow control through such a passageway may be facilitated by ventilation system features that control actuators to transition dampers between open and closed configurations. The dampers may be positioned at one or both ports of the tunnel ventilation system such that opening and closing of the dampers manages airflow through the passageway. Ventilation systems such as this may be used for emergency ventilation control and may need to operate under extreme environmental conditions. For example, actuators of a ventilation system (e.g., a tunnel ventilation system) may need to actuate to provide or prevent ventilation while being exposed to extreme temperatures. It would not be unusual for such a system to need to operate with ambient temperatures reaching up to 400° C. or even more. Accordingly, it is now recognized that actuators for such ventilation systems can benefit from being housed within a protective enclosure having features in accordance with present embodiments, as will be described in further detail below.

Present embodiments are directed to improved protective enclosures for actuators. The actuators may be used in HVAC systems, waterside systems, airside systems, building management systems (BMS), and the like. The actuators may be designed to actuate a flow manager (e.g., a valve, damper) to control fluid flow through a flow path or passage (e.g., a valve body, duct, tunnel). This may be done under conditions that require protection of the actuators within respective housings, such as protective enclosures in accordance with present embodiments. The protective enclosures in accordance with present embodiments may house actuators and allow for efficient operation of the actuators under extreme and/or potentially damaging environmental conditions (e.g., high levels of moisture, high temperatures) to control ventilation adjusters (e.g., dampers, louvers) and, thus, manage ventilation characteristics (e.g., airflow levels) of a ventilation system.

An enclosure in accordance with present embodiments may include a hollow member, a plate connected (e.g., welded) to a first end of the hollow member, and a cover detachably coupled to a second end of the hollow member. The cover cooperates with the hollow member to facilitate access to an interior of the hollow member for storing and accessing at least one actuator. The hollow member, the plate, the cover, or a combination thereof may include an inner layer and an outer layer (e.g., metal sheets or plates) with one or more insulation layers (e.g., ceramic fiber) sandwiched between the inner layer and the outer layer. Further, in some embodiments, one or more gaskets are provided between the cover and the hollow member to provide for a sealing engagement between the cover and the hollow member. This sealing engagement may prevent water or other fluid from entering the enclosure and damaging (e.g., causing corrosion) a housed actuator.

In accordance with present embodiments, the hollow member is constructed with a limited need for fasteners by, for example, coupling a single housing wall to itself (forming only one seam of the housing wall) to form a curved enclosure. That is, the shape formed may be generally or partially in the form of a cylinder, frustum, cone, prism incorporating curved sides, or other three dimensional curvilinear structure. Further, the hollow member in accordance with present embodiments may be provided with one or more insulation layers sandwiched between inner and outer layers of the housing wall. The one or more insulation layers may provide spatial efficiency, operational efficiency, and facilitate maintenance related to the enclosure because they are incorporated directly into the housing wall and because of the insulation material's properties (e.g., properties that insulate against extreme environmental temperature conditions). The insulation provided in accordance with present embodiments may also resists moisture entering the enclosure and interfering with an actuator housed therein. For example, the insulation may repel water. Furthermore, present embodiments may incorporate one or more gaskets located between coupled features (e.g., a hollow member and cover) to protect the actuator from moisture.

Traditionally, actuators are protected with insulation bags or box (e.g., box-shaped) enclosures. For example, a traditional actuator enclosure may be generally cuboidal in shape and formed from panels that are coupled together via numerous fasteners. A traditional insulation bag may include a soft insulating cover that can be wrapped around or otherwise disposed about the actuator. As discussed below, present embodiments have numerous advantages over such traditional equipment.

A traditional actuator enclosure, such as a cuboidal enclosure, may be employed as an actuator housing in a conventional ventilation system. The cuboidal enclosure may be coupled to dampers of the ventilation system and may house the actuator, which is operable to transition dampers of the ventilation system between open and closed configurations. A conventional cuboidal enclosure is constructed using a plurality of panels. The plurality of panels are coupled via a plurality of fasteners and form multiple seams. Specifically, for example, each panel of the plurality of panels may be provided with a flange and each flange may be orthogonal to a flat surface of another panel from the plurality of panels. Indeed, the flanges of adjacent panels may be positioned to overlap with each other and the flanges overlapping with each other may be connected using one or more fasteners, thereby requiring a high part count of the cuboidal enclosure and numerous openings through which the fasteners extend.

When there is a high level of moisture in the environment (e.g., rain is falling or condensation is accumulating), the large number of fasteners (and associated openings) used in such a conventional cuboidal enclosure may lead to water penetration inside the cuboidal enclosure and even inside of an actuator being housed by the enclosure. Due to water penetration, the cuboidal enclosure may fail to protect the actuator it is housing from moisture, which often leads to actuator damage. For example, the actuator may be susceptible to corrosion from exposure to excessive moisture within the enclosure. In addition, it is now recognized that the shape of the traditional cuboidal enclosure is susceptible to deformation (e.g., bending of flat panel components), especially when exposed to high temperatures and/or when the enclosure is cantilevered to a supporting structure such that gravity causes a larger moment about the coupling. Further, the block shape of traditional enclosures (e.g., traditional cuboidal enclosures) can cause a substantial pressure drop across the exterior thereof, which is disadvantageous because many ventilation systems essentially require placement of the enclosure within an airflow path. Further, it is now recognized that conventional cuboidal enclosures possess weak insulation properties and low heat resistance and, thus, may be susceptible to a high level of deformation during exposure to extreme temperature conditions. These and other issues related to such traditional enclosures can result in challenging and expensive maintenance operations (e.g., repair of enclosures, actuators, and so forth).

As set forth above, it is now recognized that forming an actuator enclosure in the conventional manner results in inefficiencies, such as a high parts count (e.g., numerous panels and fasteners that are separately provided), relative to present embodiments. Additionally, it is now recognized that such traditional actuator enclosures do not sufficiently protect an enclosed actuator from moisture. Indeed, relative to present embodiments, the use of the larger number of fasteners and seams are more likely to result in increased water penetration into the enclosure. Additionally, present embodiments are spatially more efficient (e.g., less bulky) and facilitate improved insulation (e.g., increased heat resistance) relative to traditional cuboidal enclosures. Further, it is now recognized that such characteristics can make maintenance of traditional actuator enclosures more challenging, time consuming, and expensive than that of present embodiments. Present embodiments also efficiently utilize brackets, handles, latches, and seals to provide support (e.g., to limit deformation), accessibility, and toolless engagements.

Further still, traditional enclosures, such as insulation bags, have similar deficiencies with respect to present embodiments. Insulation bags used to insulate actuators tend to be made of bulky material. Further, the material used to make insulation bags are generally limited with respect to protecting from moisture and extreme temperature conditions. In fact, insulation bags may actually draw in moisture. Further, conventional insulation bags can be expensive to maintain because they have a high probability of malfunctioning due to moisture related issues. Thus, it is now recognized that present embodiments are more spatially efficient than bulky insulation bags, facilitate more resistance to accumulation of moisture relative to insulation bags, operate better when exposed to atmospheric conditions, better resist extreme temperatures, and limit expenses associated with malfunctioning due to moisture accumulation in insulation bags.

Turning now to the drawings, FIG. 1 illustrates an embodiment of a heating, ventilation, and/or air conditioning (HVAC) system for environmental management that may employ one or more HVAC units. As used herein, an HVAC system includes any number of components configured to enable regulation of parameters related to climate characteristics, such as temperature, humidity, air flow, pressure, air quality, and so forth. For example, an “HVAC system” as used herein is defined as conventionally understood and as further described herein. Components or parts of an “HVAC system” may include, but are not limited to, all, some of, or individual parts such as a heat exchanger, a heater, an air flow control device, such as a fan, a sensor configured to detect a climate characteristic or operating parameter, a filter, a control device configured to regulate operation of an HVAC system component, a component configured to enable regulation of climate characteristics, or a combination thereof. An “HVAC system” is a system configured to provide such functions as heating, cooling, ventilation, dehumidification, pressurization, refrigeration, filtration, or any combination thereof. For example, an HVAC system may include a tunnel ventilation system. The embodiments described herein may be utilized in a variety of applications to control climate characteristics, such as residential, commercial, industrial, transportation, or other applications where climate control is desired.

In the illustrated embodiment, a building 10 is air conditioned by a system that includes an HVAC unit 12. The building 10 may be a commercial structure or a residential structure. As shown, the HVAC unit 12 is disposed on the roof of the building 10. However, the HVAC unit 12 may be located in other areas, such as equipment rooms or areas adjacent the building 10. The HVAC unit 12 may be a single packaged unit containing other equipment, such as a blower, heat exchangers, integrated air handler, and/or auxiliary heating unit. In other embodiments, the HVAC unit 12 may be part of a split HVAC system, which includes an outdoor HVAC portion and an indoor HVAC portion.

The HVAC unit 12 is an air-cooled device that implements a refrigeration cycle to provide conditioned air to the building 10. Specifically, the HVAC unit 12 may include one or more heat exchangers across which an air flow is passed to condition the air flow before the primary air flow is supplied to the building. In the illustrated embodiment, the HVAC unit 12 is a rooftop unit (RTU) that conditions a supply air stream, such as environmental air and/or a return air flow drawn from the building 10. After the HVAC unit 12 conditions the air flow, the air flow, also referred to herein as a primary air flow, is supplied to the building 10 via ductwork 14 extending throughout the building 10 from the HVAC unit 12. For example, the ductwork 14 may extend to various individual floors or other sections of the building 10. In certain embodiments, the HVAC unit 12 may be a heat pump that provides both heating and cooling to the building with one refrigeration circuit configured to operate in different modes. In other embodiments, the HVAC unit 12 may include one or more refrigeration circuits for cooling an air flow and a furnace for heating the air flow. The primary air flow supplied to the building 10 by the HVAC unit 12 may include environmental air, such as air from outside the building 10, and/or recirculated air from within the building 10, which may or may not be actively and/or passively heated or cooled by the HVAC unit 12. For example, the HVAC unit 12 may operate in a recirculating or economizer mode, such that the supply air flow, and thus the primary air flow, is not actively heated or cooled.

A control device 16, one type of which may be a thermostat, may be used to designate a desired temperature of a conditioned space 18 within the building 10. The control device 16 also may be used to control the flow of air, such as volume, through the ductwork 14 to different areas within the conditioned space 18. For example, the control device 16 (e.g., an automation controller, such as a programmable logic controller) may be used to regulate operation of one or more components of the HVAC unit 12 or other components, such as dampers 20, fans 22, and/or terminal units within the building 10 that may control the flow of air through and/or from the ductwork 14. As a specific example, the control device 16 may control operation of the dampers 20 to manage a tunnel ventilation effect. In some embodiments, other devices may be included in the system, such as pressure and/or temperature transducers or switches that sense the temperatures and pressures of the conditioned air, return air, and so forth. Moreover, the control device 16 may include computer systems that are integrated with or separate from other building control or monitoring systems, including systems that are remote from the building 10.

Specifically, for example, the control device 16 may control the dampers 20 via an actuator 22 disposed in a hollow member of a protective enclosure or housing 24 in accordance with present embodiments. The hollow member of the housing 24 may be generally or partially in the form of a cylinder, frustum, cone, prism incorporating curved sides, or the like. Further, the hollow member may incorporate one or more insulation layers sandwiched between inner and outer layers of a housing wall. The control device 16 may operate the actuator 22 under various conditions (e.g., extreme atmospheric conditions) to control ventilation (e.g., block or open ventilation to control a tunnel effect) and the housing 24 may keep the actuator 22 operational even under severe conditions by insulating it from the surrounding environment, avoiding deformation, and preventing corrosive encroachment.

FIG. 2 is a perspective view of a ventilation system 100 (e.g., a tunnel ventilation system) in accordance with present embodiments. In the illustrated embodiment, the ventilation system 100 includes a damper 102, which may be an exhaust air damper, mixing damper, outside air damper, or the like. Further, the ventilation system 100 includes an enclosure 104 that is tubular in shape and houses an actuator that operates the damper 102 (e.g., causes the damper 102 to move between open and closed configurations) via a linkage 103. While other three-dimensional curvilinear shapes (e.g., conical, partial prolate spheroid) may be employed in accordance with present embodiments, in the illustrated embodiment, the enclosure 104 is substantially cylindrical in shape.

In the illustrated embodiment, the enclosure 104 is coupled to (e.g., mounted on) the damper 102. Mounting of the enclosure 104 to the damper 102 may be the most practical mounting position based on aspects or limitations of the overall ventilation system. For example, the damper 102 may be part of a tunnel ventilation system and the actuator (within the enclosure 104) may be positioned within a respective tunnel or airflow path of the tunnel ventilation system because no alternatives for placement reasonably allow for operable engagement between the actuator and the damper 102 (e.g., via the linkage 103). Indeed, many tunnel ventilation systems do not practically allow for installation of a damper actuator outside of the airflow path through the tunnel. Because the enclosure 104 houses the actuator, the enclosure 104 may also need to be positioned in the airflow path. Due to this positioning within the airflow path, the shape of the enclosure 104 will be relevant to airflow characteristics through the ventilation system 100. Because, in accordance with present embodiments, the enclosure 104 has a curved shape (e.g., a tubular shape) and the curvature is aligned with a direction of airflow 105, it can reduce resistance to the airflow relative to traditional boxy or cuboidal shapes. Thus, energy can be conserved (e.g., lower powered fans can be used to direct the airflow) because the three-dimensional curvilinear body of the enclosure 104 more readily allows fluid flow to pass over it than a more traditional angular or boxy structure, such as a cuboidal enclosure.

The enclosure 104 may be mounted on the damper 102 using one or more clamps 107, which may facilitate rapid attachment of the enclosure to the damper 102 and rapid removal of the enclosure 104 from the damper 102. It should be noted that, in some embodiments, the enclosure 104 may be mounted separately from the damper 102 in a position that allows an actuator within the enclosure 104 to operably engage (e.g., via the linkage 103) with the damper 102. In some embodiments, the one or more clamps 107 may be C-shaped clamps, tool-less clamps, or other types of clamps. Further, in some embodiments, the enclosure 104 may be mounted on the damper 102 at one or more mounting locations using any of various mounting techniques (e.g., welding, fasteners, brackets, extensions). For example, in one embodiment, an attachment 110 (which may operate as a handle 110 or a mounting bracket 110) may be used to mount the enclosure 104 to the damper 102. By providing an additional mount location for the enclosure 104, the attachment 110 may assist in resisting deformation of the enclosure 104 and/or the clamp 107, such as bending due to unbalanced weight resulting from cantilevering. Cantilevering can encourage deformation of certain features (e.g., a body of the enclosure 104), especially under extreme heat, which can cause interference between the enclosure 104 and operable aspects (e.g., a shaft) of the housed actuator. The attachment 110 (operating at the mounting bracket 110) may serve as an extension that spans the width of the damper 102 or some other fixed feature to which the enclosure 104 is mounted. Thus, more substantial support than cantilevering or even multiple couplings that are not sufficiently spaced apart may be provided by the attachment 110 in such an operational mode. Further, when functioning as the handle 110, the attachment 110 can be used to facilitate maintenance activities relative to the enclosure 104 (e.g., facilitate carrying the enclosure 104, gripping the enclosure 104, movement/control of a position of the enclosure 104). Thus, present embodiments may employ the attachment 110 as the mounting bracket 110 and/or the handle 110, which creates physical and operational efficiencies.

While in the illustrated embodiment, the enclosure 104 is cylindrical and a length of the cylindrical shape is oriented substantially horizontally. Orientation of the enclosure 104 relative to other aspects of the ventilation system 100 (e.g., the damper 102) may be customized as desired or needed. For example, the enclosure 104 may be positioned based on the direction of airflow 105. As another example, the one or more clamps 107 and/or the attachment 110 may be positioned based on a desired orientation of the enclosure 104 relative to a support structure (e.g., the damper 102), airflow, and/or gravity.

The enclosure 104 comprises a hollow member 114, which may have a unibody structure (e.g., a structure formed from a single unit, such as a bent sheet of metal or a molding). As noted above, the enclosure 104 may be generally tubular in shape and the hollow member 114 may have a tubular structure as well, forming a tubular interior. The tubular nature of the hollow member 114 may account for its unibody structure. As an example, the hollow member 114 may include a single wall coupled to itself at only one seam (e.g., seam 115) or may be seamless (e.g., molded). However, in accordance with another embodiment of the present disclosure, the hollow member 114 may comprise a plurality of sides. At least one side of the plurality of sides may be non-perpendicular to the adjacent sides. For example, in some embodiments, the plurality of sides of the hollow member 114 may have equal lengths and all adjacent sides of the plurality of sides may be non-perpendicular to each other. However, in some other embodiments, the plurality of sides may not have equal lengths. In such a case, at least one side of the plurality of sides may be non-perpendicular to adjacent sides. Further, in some embodiments, the hollow member 114 may have portions with varied curvature (e.g., varied diameters). That is, the hollow member 114 may have a step profile, a conical profile, a partially conical profile, a profile that is chamfered from at least one end, parabolic, curved, oval, hollow, cylindrical, pentagonal, hexagonal, and the like.

The hollow member 114 may comprise a body 120 and a cover 124 that is displaceable with respect to the body 120 to facilitate easy access to an interior of the enclosure 104. For example, the body 120 and the cover 124 may facilitate easy access to an actuator 128 (shown in FIG. 3 ) housed within the enclosure 104. In some embodiments, the cover 124 may be removed from the body 120 or vice-versa with assistance from the attachment 110 (operating as the handle 110) to facilitate access to the actuator 128. For example, the cover 124 may be in threaded engagement with the body 120 and the handle 110 (which may extend from the body 120 or the cover 124) may facilitate gripping and toolless detachment by rotating and disengaging the threads of the cover 124 and the body 120. In some embodiments, the body 120 and the cover 124 may be angularly displaceable with respect to one another (e.g., via one or more hinges) coupled therebetween.

In some embodiments, the cover 124 may be provided with a slot, hole, or other opening for passage of a mechanical operator 130 (as shown in FIG. 3 ) of the actuator 128 out of the enclosure 104. The mechanical operator 130 may include one or more of a driveshaft, a linkage, and the like. Further, one or more gaskets may be provided between the body 120 and the cover 124 to prevent moisture from traversing between the body 120 and the cover 124 while they are engaged and to prevent accumulation of moisture within the enclosure 104. Additionally, in some embodiments, the hollow member 114 may have a portion that acts as a window and can be opened or peered through to facilitate access to the interior of the enclosure 104.

A wall or base 132, such as a substantially circular plate, may be connected to a first end of the hollow member 114 opposite a second end of the hollow member 114 that is configured to couple with the cover 124. In some embodiments, the base 132 may be connected to the hollow member 114 via fasteners (e.g., screws), one or more joints (e.g., mortise and tenon joints, half-blind dovetail joints, through dovetail joints, sliding dovetail joints, box joints, dowel joints, biscuit joints) or other fastening techniques (e.g., welding, snug fit). In some embodiments, the base 132 may be integral with the hollow member 114 (e.g., molded together).

FIG. 3 is a schematic cross-sectional representation of the actuator 128 housed within the enclosure 104 of the ventilation system of FIG. 2 , in accordance with present embodiments. The enclosure 104 includes the hollow member 114, the base 132, and the cover 124. Further, in the illustrated embodiment, each of the hollow member 114, the plate 132, and the cover 124 includes an inner layer 136 and an outer layer 138. In some embodiments, only one or two of the hollow member 114, the base 132, and the cover 124 may include the inner layer 136 and the outer layer 138. In some embodiments, the inner layer 136 and the outer layer 138 may include one or more metal sheets (e.g., stainless steel sheets). Further, one or more insulation layers 140 (e.g., ceramic fiber layers) may be sandwiched between the inner layer 136 and the outer layer 138. In some embodiments, the one or more insulation layers 140 may be made of any suitable material capable of providing adequate insulation for desired operational characteristics. The one or more insulation layers 140 and their insulation properties may allow the enclosure 104 to withstand extreme temperature conditions, typically, for a certain duration of time. However, this duration can be increased by increasing the number of insulation layers 140. For example, a single layer of insulation may allow the enclosure 104 to withstand an outside temperature of 400 degrees Celsius for a duration of 2 hours while maintaining an inside temperature of less than 100 degrees Celsius (or even less than 90 degrees Celsius). Additional layers may improve these values.

The hollow member 114 of the enclosure 104 may provide a curvilinear (e.g., semi-circular) airflow about its exterior that may limit pressure drop across the enclosure 104. As noted above, this is beneficial when the enclosure 104 is placed within an airflow path (e.g., a tunnel) of the ventilation system 100. In some embodiments, the hollow member 114 (or at least an outer boundary thereof) of the enclosure 104 may be provided with a single folded sheet welded at one side. The hollow member 114 may also help to reduce a number of fasteners used in the enclosure 104 as compared to the traditional cuboidal enclosure designs discussed above. In addition, the hollow member 114, having a smaller number of fasteners relative to traditional enclosures, may reduce an overall part count of the enclosure 104, thereby reducing inefficiencies in assembly and the bulkiness of the tunnel ventilation system 100. In some embodiments, the enclosure 104, in accordance with present embodiments, may help to reduce part count by 75% as compared to a traditional cuboidal enclosure. Further, unlike a traditional cuboidal enclosure, water penetration due to fasteners (and corresponding openings for the fasteners to pass through) is reduced in the enclosure 104.

As shown in FIG. 3 , the enclosure 104 houses the actuator 128. More specifically, in the illustrated embodiment, the actuator 128 is housed within the hollow member 114 of the enclosure 104. The geometry (e.g., at least one dimension) of the enclosure 104 is such that a sufficient clearance or gap is provided between the hollow member 114 and the actuator 128 to allow for installation and operation of the actuator 128 within the enclosure 104. In some embodiments, the actuator 128 may be a damper actuator, or any other type of actuator that can be used in a HVAC unit, a ventilation system (e.g., a tunnel ventilation system, an emergency ventilation system), or the like. For an example, the actuator 128 can be one of, but not limited to, a pneumatic actuator, an electrical actuator, a hydraulic actuator, or the like. The actuator 128 can be coupled to the damper 102 and can be used to drive the damper 102 between an open position and a closed position. As a specific example, the actuator 128 may include a motor 142 and a drive device, such as the mechanical operator 130 (e.g., drive shaft, linkage), driven by the motor 142. The motor 142 can be a brushless direct current (BLDC) motor. The mechanical operator 130 may be coupled (directly or indirectly) to a movable HVAC component (e.g., the damper 102) for driving the HVAC component between various different positions or configurations. A bracket 144 (e.g., an actuator mounting bracket) may be provided between the actuator 128 and the cover 124 to provide a support for mounting the actuator 128 and to facilitate installation of the actuator 128 within the enclosure 104. For example, the actuator 128 may be coupled to the cover 124 via the bracket 144 and then installed in the enclosure 104 by coupling the cover 124 to the hollow member 114. In some embodiments, the enclosure 104 may be configured to accommodate a plurality of actuators and/or actuator types (e.g., actuators with different dimensions, actuator models provided by different manufacturers).

FIG. 4 is an exploded perspective view of the enclosure 104 housing the actuator 128 in accordance with an embodiment of the present disclosure. In the illustrated embodiment of FIG. 4 , the enclosure 104 includes the hollow member 114, the base 132 and the cover 124. The actuator 128 is housed within and between the enclosure and the cover 124, which are coupled about a gasket 150 to seal the actuator 128 within the enclosure 104. Specifically, in the illustrated embodiment, the gasket 150 is positioned between and engaged with the cover 124 and the hollow member 114, which are coupled in a sealed configuration using fasteners 152 that extend through a flange 154 of the hollow member 114 and through at least a portion of the cover 124. Specifically, in the illustrated embodiment, the fasteners 152 extend through openings 156 in the flange 154 and a face 158 of the cover 124. However, in other embodiments, multiple flanges and orientations of engagement may be employed. For example, the flange 154 may angle toward the cover 124 to facilitate a sheathing engagement therewith and the fasteners 152 may extend through a perimeter 160 of the cover 124. The gasket 150 may be made of flexible material to fill gaps and protect the actuator 128 from accumulation of moisture within the hollow member 114 that can occur when moisture from the environment leaks into the hollow member 114 (e.g., via gaps between the hollow member 114 and the cover 124). Unlike traditional enclosures for actuators (e.g., traditional cuboidal enclosures), moisture related damage, such as corrosion, caused to the actuator 128 may be prevented by the gasket 150 and by the limited use of fasteners that can provide access points for moisture into the enclosure 104. In addition, the enclosure 104 may be constructed such that it is rated with a NEMA 4/4X (National Electrical Manufacturers Association) rating and offers protection from damaging environmental conditions, such as dust, dirt, rain, ice formation, corrosion, and so forth.

FIG. 5 is an exploded perspective view of the enclosure 104 in accordance with an embodiment of the present disclosure. As previously noted and illustrated in FIG. 5 , the cover 124 of the enclosure 104 is detachable from the hollow member 114. In the illustrated embodiment, the flange 154 is provided on an end of the hollow member 114 to facilitate attachment of the cover 124. Additionally, a latch 164 is provided to facilitate toolless coupling and decoupling of the hollow member 114 and the cover 124. For example, upon the cover 124 abutting with the flange 154, the latch 164 may pass over an outer edge of the cover 124 (or a flange of the cover 124) to secure the cover 124 adjacent the flange 154. In the illustrated embodiment, the latch 164 is permanently attached to the flange 154 and configured to flex over the cover 124 to engage with an outer face of the cover 124. However, in other embodiments, the latch 164 may be a separate piece that flexes to extent about the flange 154 and the cover 124 to engage both of them and hold them adjacent one another (e.g., using gravity and moment to leverage the components together). Further, the cover 124 may also include a flange that can be engaged with the latch 164. Further still, the cover 124 may incorporate the latch 164 (instead of the hollow member 114 incorporating the latch 164) or an additional latch 164 to facilitate cooperative engagement. Indeed, while the latch 164 is shown without additional latches, it is noted that the latch 164 represents any number of latches 164 that may be employed separately or as integrated components in accordance with present embodiments to secure the hollow member 114 and the cover 124. For example, it may be efficient to include two or more latches 164 on opposing sides of the hollow member 114 and the cover 124 to distribute coupling forces. Additionally, the flanges 154 and latches 164 may provide support while detaching or attaching the cover 124 to the hollow member 114. For example, one or more of the latches 164 may retain the hollow member 114 and the cover 124 adjacent to one another and in proper alignment to facilitate further attachment via the fasteners 152. With this in mind, it may be preferable to only include a single latch 164 that temporarily holds the cover 124 adjacent the hollow member 114 (e.g., from an upper latching position relative to gravity) for coupling via the fasteners 152. While a particular embodiment is illustrated in FIG. 5 , it should be noted that one or more latches 164 and flanges 154 may be shaped in different ways and operable to facilitate engagement (e.g., C-shaped and flexible).

FIG. 6 is an exploded perspective view of the enclosure 104 and layers of the enclosure 104 in accordance with present embodiments. As illustrated, the hollow member 114 is shown in exploded form 202 and in assembled form 204. In the exploded form 202, the inner layer 136 is shown as an inner shell 206, the outer layer 138 is shown as an outer shell 208, and the insulation layer 140 is shown as an insulation filler 210 (e.g., ceramic fibers) disposed between the inner shell 206 and outer shell 208. The flange 154 is also shown exploded from other components of the hollow member 114. However, it may be integral with or coupled to at least the outer shell 208. In one embodiment, the flange 154 is coupled to the inner shell 206 and the outer shell 208 at a first end 220 of the hollow member 114 and the insulation filler 210 is disposed between the inner shell 206 and the outer shell 208 from a second end 222 (opposite the first end) of the hollow member 114.

As with the hollow member 114, the base 132 and the cover 124 each includes a respective assembly of components. As illustrated, the base 132 is formed from an external base plate 230 as the outer layer 138, an internal base plate 232 as the inner layer 136, and a base insulation puck 234 as the insulation layer 140. A base shell 236 couples the internal base plate 232 to the external base plate 230 about the insulation layer 140 and holds the base 132 together. Further, the attachment 110 couples to the external base plate 230 (e.g., via welding) and may include coupling features that extend through one or more layers of the base 132. Similarly, the cover 124 is formed from an outer cover plate 236 as the outer layer 138, an inner cover plate 238 as the inner layer 136, and a cover insulation puck 240 as the insulation layer 140. A cover shell 242 couples the internal cover plate 232 to the external cover plate 230 about the cover insulation puck 240 and holds the cover 124 together. The bracket 144 couples (e.g., via welding) to the internal cover plate 232 and extends into the hollow member 114 therefrom. For additional support, the bracket 144 may include coupling features that coupled with multiple layers of the cover 124. The bracket 144 may operate as an actuator mounting bracket and may include features, such as receptacles 244 for coupling with the actuator 128 and allowing the mechanical operator 130 (e.g., a driveshaft) to extend out of the enclosure 104. As previously noted, the actuator 128 may be coupled to the cover 124 (e.g., via the bracket 144) prior to insertion of the actuator 128 into the hollow member 114. Additionally, in some embodiments, one or more ports (such as the receptacles 244) may be provided in the base 132 for the mechanical operator 130 to extend through.

In accordance with present embodiments, the enclosure 104 is designed to safeguard the actuator 128 disposed inside from high temperature applications (e.g., environment conditions experiencing temperatures of 400 degrees Celsius and greater for at least 2 hours). A typical temperature at which an actuator (e.g., the actuator 128) can function is around 100 degrees Celsius. Above 100 degrees Celsius often damages electronic circuits of actuators. Accordingly, finite element thermal analysis was performed on the enclosure 104 with environmental temperatures at greater than 400 degrees Celsius (i.e., an air stream temperature of 430 degrees Celsius) and with a 2.5 inch thick layer of ceramic fibers as the insulation layer 140. After 2 hours of this exposure, the thermal analysis of the enclosure 104 demonstrated a range of temperature values that the enclosure 104 can withstand. For example, the thermal analysis indicated that the enclosure 104 can reach an outer temperature of 430.5° C. while maintaining an average inner temperature of approximately 89° C. A gradient of temperatures from the thermal analysis is shown in the cross-sectional temperature gradient diagram of FIG. 7 . As previously noted, the enclosure 104 comprises the hollow member 114, the base 132, and the cover 124. Further, at least one of the hollow member 114, the base 132, and the cover 124 may include the one or more insulation layers 140 sandwiched between the inner layer 136 and the outer layer 138. The one or more insulation layers 140 are of ceramic fiber and help in achieving the operational requirements (temperature targets).

A deformation analysis of the enclosure 104 was also performed and demonstrated a range of deformation values of the enclosure 104 when the enclosure 104 is exposed to extreme temperature conditions. When the enclosure 104, in the form of a cantilevered cylinder, was subjected to high temperatures, thermal stress and self-weight of the actuator 128 can cause deformation in the bracket 144. After 2 hours of high heat exposure, deformation was analyzed and identified deflection was within acceptable criteria (e.g., L/360 inches, where L is the length of component). In one analysis, a maximum value of deformation of the enclosure 104 was 0.0032 inches. As compared to a traditional cuboidal enclosure, the enclosure 104 of the present disclosure is subjected to minimum deformation and can withstand extreme temperature conditions. Due to minimum deformation, a probability of malfunctioning of the enclosure 104 is also reduced significantly.

Embodiments of the present disclosure address shortcomings of conventional systems. For example, traditional cuboidal enclosures have a high pressure drop across their exterior and a high part count relative to present embodiments. Present embodiments limit pressure drop across the exterior and limit parts count with the curvilinear (e.g., unibody) shape of the hollow member.

Additionally, traditional cuboidal enclosures lack the protection from moisture provided in accordance with present embodiments. Present embodiments utilize the geometric structure to limit fasteners (and associated leak points) along with a gasket to limit invasive moisture. Further, traditional cuboidal enclosures are bulky and have weak insulation properties relative to present embodiments. Present embodiments include one or more insulation layers sandwiched between inner and outer layers of the enclosure. Thus, the enclosure of the present disclosure is cost effective and easy to maintain as compared to the conventional enclosures.

The specific embodiments described above have been shown by way of example, and it should be understood that these embodiments may be susceptible to various modifications and alternative forms. It should be further understood that the claims are not intended to be limited to the particular forms disclosed, but rather to cover all modifications, equivalents, and alternatives falling within the spirit and scope of this disclosure. 

What is claimed is:
 1. An enclosure for an actuator of an HVAC unit, the enclosure comprising: a hollow member comprising an inner shell, an outer shell, and an insulation layer disposed between the inner shell and the outer shell; a cavity within the inner shell configured to receive an actuator; an exterior surface of the hollow member having curvilinear shape configured to limit resistance to airflow over the exterior surface; a base connected to a first end of the hollow member; and a cover detachably coupled to a second end of the hollow member opposite the first end.
 2. The enclosure of claim 1, wherein the base and the cover each comprise an outer layer, inner layer, and insulation disposed between the outer layer and the inner layer.
 3. The enclosure of claim 1, wherein the hollow member comprises a unibody structure.
 4. The enclosure of claim 3, wherein the hollow member is molded or comprises a single wall coupled to itself.
 5. The enclosure of claim 1, wherein the inner shell, the outer shell, and the insulation layer combine to form a single wall that defines the hollow member.
 6. The enclosure of claim 1, wherein the curvilinear shape is tubular.
 7. The enclosure of claim 1, wherein the hollow member comprises a plurality of sides, at least one side of the plurality of sides being curved, non-perpendicular to adjacent sides, and facing a direction of airflow in a ventilation system.
 8. The enclosure of claim 1, comprising an attachment that operates as a handle or a bracket coupled to the base, wherein the base comprises a plate integral with or coupled directly to the hollow member.
 9. The enclosure of claim 1, wherein the insulation layer comprises one or more ceramic fiber layers.
 10. The enclosure of claim 1, comprising a gasket coupled between the cover and the hollow member.
 11. The enclosure of claim 1, comprising an actuator mounting bracket extending from the cover into the hollow member and configured to support the actuator.
 12. The enclosure of claim 1, comprising one or more ports in the base, the mount, or both, wherein the one or more ports is configured to allow a mechanical operator of the actuator to extend outside of the enclosure through the one or more ports.
 13. The enclosure of claim 1, wherein the hollow member is formed from a single wall that only couples to itself about a single seam.
 14. The enclosure of claim 1, comprising a clamp configured to attach the hollow member to a support at a position along the hollow member and a bracket extending from the base configured to facilitate attachment to the support.
 15. A ventilation system, comprising: a damper configured to be opened and closed by an actuator to control airflow through a flow path of the ventilation system; an enclosure mounted on the damper; a hollow member of the enclosure defining a cavity configured to receive the actuator; a exterior surface of the hollow member having a curvilinear shape configured to limit resistance to the airflow passing over the enclosure; a base connected to a first end of the hollow member; and a cover detachably coupled to a second end of the hollow member opposite the first end.
 16. The ventilation system of claim 15, wherein the actuator is mounted to the cover and housed within the hollow member, and a mechanical operator of the actuator extends out of the housing to operably engage with the damper.
 17. The ventilation system of claim 16, wherein the mechanical operator comprises a driveshaft extending through an opening of the cover and a linkage coupling the driveshaft to the damper to facilitate transitioning the damper between an open configuration and a closed configuration.
 18. The ventilation system of claim 15, wherein the hollow member, the cover, and the based comprise an inner layer, an outer layer, and an insulation layer disposed between the inner layer and the outer layer such that after 2 hours spent in an environment at approximately 430 degrees Celcius, an average temperature in the enclosure remains below 90 degrees Celcius.
 19. The ventilation system of claim 15, wherein the hollow member has a unibody structure formed from a single wall that is coupled to itself at only one seam, and wherein the hollow member is mounted to the damper via one or more clamps.
 20. A tunnel ventilation system, comprising: an airflow path for ventilation of an interior space; a damper configured to transition between an open configuration and a closed configuration to control airflow through the airflow path; an actuator configured to transition the damper between the open configuration and the closed configuration via a mechanical operator directly or indirectly coupled to the damper; an enclosure mounted on the damper and positioned within the airflow path; a hollow member of the enclosure formed from an inner shell, an outer shell, and an insulation layer disposed between the inner shell and the outer shell, wherein the hollow member defines a cavity in which the actuator is disposed; a exterior surface of the hollow member having a curvilinear shape that is configured to limit resistance to the airflow passing over the enclosure; a base connected to a first end of the hollow member; and a cover detachably coupled to a second end of the hollow member opposite the first end, wherein the cover comprises a port through which the mechanical operator extends. 